Evolution of Operating Systems usage

I needed this statistics and I'm sure they're somewhere, but I don't know where. So, I went to Wikipedia which has the updated numbers but not something showing the progress. Fortunately, wiki's have revision history, so it was fairly easy to compile what I wanted. Here it is, for the sake of others (or me) not needing to go to the same hassle again.

Wikipedia page used as a source (by using several different revisions of this document)

Q4   2004 - Windows 96.34%; Apple  3.25%; Linux 0.29%
Q1   2005 - Windows 96.21%; Apple  3.40%; Linux 0.29%
Q2   2005 - Windows 96.10%; Apple  3.50%; Linux 0.31%
Q3   2005 - Windows 96.03%; Apple  3.55%; Linux 0.32%
Q4   2005 - Windows 95.50%; Apple  4.11%; Linux 0.30%
Q1   2006 - Windows 95.29%; Apple  4.30%; Linux 0.31%
Q2   2006 - Windows 95.08%; Apple  4.40%; Linux 0.41%
Q3   2006 - Windows 95.01%; Apple  4.45%; Linux 0.44%
Q4   2006 - Windows 94.10%; Apple  5.41%; Linux 0.38%
Q1   2007 - Windows 93.17%; Apple  6.22%; Linux 0.45%
Q2   2007 - Windows 92.78%; Apple  6.23%; Linux 0.74%
Sep. 2007 - Windows 89.10%; Apple  4.00%; Linux 0.81%
Oct. 2007 - Windows 91.76%; Apple  4.46%; Linux 0.81%
Nov. 2007 - Windows 91.45%; Apple  4.48%; Linux 0.81%
Dec. 2007 - Windows 92.88%; Apple  4.32%; Linux 0.88%
Jan. 2008 - Windows 91.79%; Apple  4.12%; Linux 0.76%
Feb. 2008 - Windows 92.13%; Apple  4.34%; Linux 0.77%
Apr. 2008 - Windows 93.94%; Apple  4.47%; Linux 0.81%
May  2008 - Windows 93.98%; Apple  4.39%; Linux 0.83%
Jun. 2008 - Windows 94.06%; Apple  4.33%; Linux 0.89%
Jul. 2008 - Windows 93.64%; Apple  4.31%; Linux 0.90%
Aug. 2008 - Windows 91.95%; Apple  4.49%; Linux 0.96%
Sep. 2008 - Windows 93.61%; Apple  4.86%; Linux 1.04%
Oct. 2008 - Windows 90.40%; Apple  5.50%; Linux 1.16%
Nov. 2008 - Windows 90.50%; Apple  5.41%; Linux 1.16%
Dec. 2008 - Windows 90.50%; Apple  5.24%; Linux 1.16%
Jan. 2009 - Windows 91.10%; Apple  4.81%; Linux 1.02%
Feb. 2009 - Windows 91.03%; Apple  4.77%; Linux 1.04%
Mar. 2009 - Windows 90.99%; Apple  4.81%; Linux 1.05%
Apr. 2009 - Windows 91.22%; Apple  4.95%; Linux 1.13%
May  2009 - Windows 91.30%; Apple  5.01%; Linux 1.12%
Jun. 2009 - Windows 91.24%; Apple  5.06%; Linux 1.12%
Jul. 2009 - Windows 93.18%; Apple  4.59%; Linux 1.05%
Aug. 2009 - Windows 93.06%; Apple  4.59%; Linux 0.94%
Sep. 2009 - Windows 92.77%; Apple  4.59%; Linux 0.95%
Oct. 2009 - Windows 92.52%; Apple  5.87%; Linux 0.96%
Nov. 2009 - Windows 90.52%; Apple  6.48%; Linux 1.00%
Dec. 2009 - Windows 90.22%; Apple  6.57%; Linux 1.04%
Jan. 2010 - Windows 92.02%; Apple  5.79%; Linux 1.08%
Feb. 2010 - Windows 91.60%; Apple  6.58%; Linux 1.12%
Mar. 2010 - Windows 91.34%; Apple  6.63%; Linux 1.14%
Apr. 2010 - Windows 90.95%; Apple  6.61%; Linux 1.15%
May  2010 - Windows 90.88%; Apple  6.67%; Linux 1.22%
Jun. 2010 - Windows 89.53%; Apple  6.93%; Linux 1.31%
Aug. 2010 - Windows 88.92%; Apple  7.72%; Linux 1.33%
Sep. 2010 - Windows 88.66%; Apple  7.82%; Linux 1.34%
Oct. 2010 - Windows 88.40%; Apple  8.22%; Linux 1.50%
Nov. 2010 - Windows 88.01%; Apple  8.48%; Linux 1.53%
Dec. 2010 - Windows 87.82%; Apple  8.87%; Linux 1.58%
Jan. 2011 - Windows 87.54%; Apple  8.97%; Linux 1.64%
Feb. 2011 - Windows 87.36%; Apple  9.27%; Linux 1.66%
Mar. 2011 - Windows 87.15%; Apple  9.27%; Linux 1.82%
Apr. 2011 - Windows 87.00%; Apple 10.44%; Linux 1.88%
May  2011 - Windows 86.58%; Apple 10.34%; Linux 1.95%
Jun. 2011 - Windows 86.00%; Apple 10.05%; Linux 2.15%
Jul. 2011 - Windows 83.30%; Apple 10.26%; Linux 2.07%
Aug. 2011 - Windows 82.58%; Apple 10.91%; Linux 2.25%
Sep. 2011 - Windows 82.41%; Apple 11.10%; Linux 2.41%
Oct. 2011 - Windows 86.15%; Apple 10.37%; Linux 2.53%
Nov. 2011 - Windows 85.8%;  Apple 10.7%;  Linux 3.0% 
Dec. 2011 - Windows 80.83%; Apple 11.20%; Linux 3.00%
Jan. 2012 - Windows 78.66%; Apple 13.28%; Linux 3.90%
Feb. 2012 - Windows 82.11%; Apple 10.61%; Linux 2.82%
Mar. 2012 - Windows 73.38%; Apple 15.87%; Linux 5.05%
Apr. 2012 - Windows 82.21%; Apple  9.89%; Linux 3.05%
May  2012 - Windows 83.07%; Apple 12.28%; Linux 3.60%
Jun. 2012 - Windows 78.89%; Apple 15.47%; Linux 3.95%
Jul. 2012 - Windows 79.88%; Apple 13.99%; Linux 4.05%
Aug. 2012 - Windows 79.21%; Apple 14.55%; Linux 3.90%
Set. 2012 - Windows 75.88%; Apple 14.87%; Linux 3.81%
Oct. 2012 - Windows 82.76%; Apple 12.58%; Linux 4.13%
Nov. 2012 - Windows 81.74%; Apple 12.55%; Linux 3.93%
Dec. 2012 - Windows 81.54%; Apple 12.56%; Linux 3.92%
Jan. 2013 - Windows 80.84%; Apple 13.41%; Linux 3.97%
Feb. 2013 - Windows 75.89%; Apple 15.99%; Linux 5.47%
Mar. 2013 - Windows 78.85%; Apple 14.81%; Linux 4.59%
Apr. 2013 - Windows 79.01%; Apple 14.25%; Linux 4.66%
May  2013 - Windows 80.34%; Apple 12.89%; Linux 5.29%
June 2013 - Windows 73.49%; Apple 17.27%; Linux 6.68%
July 2013 - Windows 75.67%; Apple 16.05%; Linux 5.57%
Aug. 2013 - Windows 74.97%; Apple 16.12%; Linux 6.65%
Sep. 2013 - Windows 72.32%; Apple 15.69%; Linux 6.80%
Oct. 2013 - Windows 72.02%; Apple 15.85%; Linux 7.06%
Nov. 2013 - Windows 77.90%; Apple 12.96%; Linux 5.35%
Feb. 2015 - Windows 60.27%; Apple 17.70%; Linux 15.05%
Jun. 2015 - Windows 41.48%; Apple 35.75%; Linux 16.19%
Dec. 2015 - Windows 48.70%; Apple 16.33%; Linux 28.40%
May  2016 - Windows 45.00%; Apple 16.43%; Linux 33.15%
Dec. 2016 - Windows 38.31%; Apple 17.63%; Linux 39.38% 

(I intend to update this article from time to time - hopefully at least once per month.)